<?php
/**
 *--------------------------------------------------------------------
 *
 * Sub-Class - UPC Supplemental Barcode 2 digits
 *
 * Working with UPC-A, UPC-E, EAN-13, EAN-8
 * This includes 2 digits (normaly for publications)
 * Must be placed next to UPC or EAN Code
 *
 *--------------------------------------------------------------------
 * Copyright (C) Jean-Sebastien Goupil
 * http://www.barcodephp.com
 */
include_once('BCGBarcode1D.php');
include_once('BCGLabel.php');

class BCGupcext2 extends BCGBarcode1D {
	protected $codeParity = array();

	/**
	 * Constructor.
	 */
	public function __construct() {
		parent::__construct();

		$this->keys = array('0','1','2','3','4','5','6','7','8','9');
		$this->code = array(
			'2100',	/* 0 */
			'1110',	/* 1 */
			'1011',	/* 2 */
			'0300',	/* 3 */
			'0021',	/* 4 */
			'0120',	/* 5 */
			'0003',	/* 6 */
			'0201',	/* 7 */
			'0102',	/* 8 */
			'2001'	/* 9 */
		);

		// Parity, 0=Odd, 1=Even. Depending on ?%4
		$this->codeParity = array(
			array(0, 0),	/* 0 */
			array(0, 1),	/* 1 */
			array(1, 0),	/* 2 */
			array(1, 1)		/* 3 */
		);
	}

	/**
	 * Draws the barcode.
	 *
	 * @param resource $im
	 */
	public function draw($im) {
		// Starting Code
		$this->drawChar($im, '001', true);

		// Code
		for ($i = 0; $i < 2; $i++) {
			$this->drawChar($im, self::inverse($this->findCode($this->text[$i]), $this->codeParity[intval($this->text) % 4][$i]), false);
			if ($i === 0) {
				$this->DrawChar($im, '00', false);	// Inter-char
			}
		}

		$this->drawText($im, 0, 0, $this->positionX, $this->thickness);
	}

	/**
	 * Returns the maximal size of a barcode.
	 *
	 * @param int $w
	 * @param int $h
	 * @return int[]
	 */
	public function getDimension($w, $h) {
		$startlength = 4;
		$textlength = 2 * 7;
		$intercharlength = 2;

		$w += $startlength + $textlength + $intercharlength;
		$h += $this->thickness;
		return parent::getDimension($w, $h);
	}

	/**
	 * Adds the default label.
	 */
	protected function addDefaultLabel() {
		parent::addDefaultLabel();

		if ($this->defaultLabel !== null) {
			$this->defaultLabel->setPosition(BCGLabel::POSITION_TOP);
		}
	}

	/**
	 * Validates the input.
	 */
	protected function validate() {
		$c = strlen($this->text);
		if ($c === 0) {
			throw new BCGParseException('upcext2', 'No data has been entered.');
		}

		// Checking if all chars are allowed
		for ($i = 0; $i < $c; $i++) {
			if (array_search($this->text[$i], $this->keys) === false) {
				throw new BCGParseException('upcext2', 'The character \'' . $this->text[$i] . '\' is not allowed.');
			}
		}

		// Must contain 2 digits
		if ($c !== 2) {
			throw new BCGParseException('upcext2', 'Must contain 2 digits.');
		}

		parent::validate();
	}

	/**
	 * Inverses the string when the $inverse parameter is equal to 1.
	 *
	 * @param string $text
	 * @param int $inverse
	 * @return string
	 */
	private static function inverse($text, $inverse = 1) {
		if ($inverse === 1) {
			$text = strrev($text);
		}

		return $text;
	}
}
?>